The role of cardiac transcription factor NKX2-5 in regulating the human cardiac miRNAome

Deevina Arasaratnam,Kathy Koutsis,Katrina M Bell,James E Hudson,David A Elliott,Michael M Cheung,Edouard G Stanley,Charbel Abi Khalil,Elizabeth L Qian,Enzo R Porrello,Choon Boon Sim,Alicia Oshlack,David J Anderson,Anthony J White,Andrew G Elefanty

doi:10.1038/s41598-019-52280-9

Abstract

MicroRNAs (miRNAs) are translational regulatory molecules with recognised roles in heart development and disease. Therefore, it is important to define the human miRNA expression profile in cardiac progenitors and early-differentiated cardiomyocytes and to determine whether critical cardiac transcription factors such as NKX2-5 regulate miRNA expression. We used an NKX2-5eGFP/w reporter line to isolate both cardiac committed mesoderm and cardiomyocytes. We identified 11 miRNAs that were differentially expressed in NKX2-5 -expressing cardiac mesoderm compared to non-cardiac mesoderm. Subsequent profiling revealed that the canonical myogenic miRNAs including MIR1-1, MIR133A1 and MIR208A were enriched in cardiomyocytes. Strikingly, deletion of NKX2-5 did not result in gross changes in the cardiac miRNA profile, either at committed mesoderm or cardiomyocyte stages. Thus, in early human cardiomyocyte commitment and differentiation, the cardiac myogenic miRNA program is predominantly regulated independently of the highly conserved NKX2-5 -dependant gene regulatory network.

Highlights

MicroRNAs are translational regulatory molecules with recognised roles in heart development and disease
We show that the cardiomyogenic miRNA program is activated early during human cardiomyocyte differentiation in vitro
Using differentiating human pluripotent stem cells as a model we describe the miRNAome of pre-contractile cardiac progenitor cells and contracting cardiomyocytes

Summary

Introduction

MicroRNAs (miRNAs) are translational regulatory molecules with recognised roles in heart development and disease. In early human cardiomyocyte commitment and differentiation, the cardiac myogenic miRNA program is predominantly regulated independently of the highly conserved NKX2-5 -dependant gene regulatory network. The cardiogenic regulatory framework is reinforced by the direct control of certain microRNAs by critical myogenic transcription factors, including serum response factor (SRF), myocyte enhancer factor-2 (MEF2c) and GATA42–4 In addition to their key roles in heart development, miRNAs are critical to maintaining cardiac tissue homeostasis and function[1,5]. NKX2-5 was dispensable for maintenance of the human cardiomyocyte miRNAome, www.nature.com/scientificreports with no differentially expressed miRNAs identified in either cardiac committed mesodermal progenitors or immature differentiated cardiomyocytes These data suggest that, in the main, establishing the cardiomyogenic miRNA program occurs independently of the highly conserved core NKX2-5 gene regulatory network

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